Lactones and ester derivatives thereof

ABSTRACT

Spirodilactones from alkenyl or alkyl bis(succinic anhydride) and acids and alkyl esters thereof.

This is a division of application Ser. No. 549,612, filed Feb. 13, 1975.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to lactones, acids and esters. Moreparticularly, the invention relates to spirodilactones from alkenyl oralkyl bis(succinic anhydride) and acids and alkyl esters thereof.

2. Description of the Prior Art

Lactones are intra-molecular esters usually formed from hydroxy andhalogenated carboxylic acids in which the hydroxyl (or halogen) andcarboxyl groups are located in positions to lose water or halogen acid.See, for instance, Kirk-Othmer "Encyclopedia of Chemical Technology,"section entitled "Lactones."

Higher dilactones are prepared by the oxidation of higher carbocyclicketones, as well as other methods. Such higher dilactones are useful inthe production of perfumes. See, for instance, U.S. Pat. No. 2,301,827.

Poly(ester lactones) have been prepared from alkenyl succinic anhydridesand polyhydric alcohols. Such ester lactones are useful as plasticizers.See, for instance, U.S. Pat. No. 3,155,686.

SUMMARY OF THE INVENTION

In accordance with the present invention there are provided higherspirodilactones and acids and alkyl esters thereof having the structuralformulas ##STR1## in which R is alkyl or alkenyl of 2 to 28 carbon atomsand R' groups, which may be the same or different, are hydrogen or alkylgroups of 1 to 20 carbon atoms each.

The novel spirodilactones and cyclic keto acids and esters thereof ofthe invention are multifunctional: the acids are useful as petroleumcomposition rust inhibitors, the esters as plasticizers and the lactonesas intermediates in the preparation of paper sizes, resins, polymers,etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Alkenyl bis(succinic anhydride) compounds, hereinafter noted as ABSA forconvenient reference, are prepared by reacting one mol of monoolefinicaliphatic hydrocarbon of from about 3 to 30 carbon atoms with 2 moles of2,3-unsaturated-1,4-dicarboxylic acid anhydrides. The reaction of themonoolefinic hydrocarbon with the unsaturated dicarboxylic acidanhydride is thermal and noncatalytic. The reactants are heated at atemperature of at least about 150° C, but below the decompositiontemperatures at which CO₂ is formed.

The spirodilactone from alkyl or alkenyl bis(succinic anhydride) of thepresent invention is prepared by heating alkyl or alkenyl bis(succinicanhydride) to effect removal of CO₂. One mol of CO₂ is lost, and thenovel spirodilactone results in accordance with the following schematicequation and structural formulas, using the alkenyl analog forillustration: ##STR2## in which R" is hydrogen or alkyl of 1 to 26carbon atoms.

In the case of propenyl or isobutenyl bis(succinic anhydride), thedilactone has the schematic formula: ##STR3## in which R'" is hydrogenor a methyl group.

The cyclic keto esters have the schematic formula: ##STR4## in which R'"is hydrogen or a methyl group and R' groups, which may be the same ordifferent, are hydrogen or alkyl groups of 1 to 20 carbon atoms each.

The cyclic keto diester of the spirodilactone of the present inventionis prepared by conventional transesterification with alcohol. Thealcohols may be aliphatic or cycloaliphatic alcohols of 1 to 20 carbonatoms. However, preferred alcohols are the alkyl alcohols of from 1 to 8carbon atoms, since the esters derived therefrom are particularly suitedas plasticizers.

The following examples further illustrate the preparation of the novelspirodilactones from alkenyl bis(succinic anhydride) and acids andesters thereof in accordance with the present invention. Unlessotherwise indicated, percentages are on a weight basis.

EXAMPLES EXAMPLE 1 PREPARATION OF C₈ ABSA

Octenyl succinic anhydride (1383 g, 6.6 mols) and maleic anhydride (429g, 4.4 mols) were placed in a 2-liter round-bottom flask equipped withstirrer, condenser and thermometer. The reaction was carried out for 18hours by heating with stirring in an oil bath at 200° C. The product wasdistilled through a wiped-film evaporator at 140° C and 0.5-1 mm Hg toremove unconverted octenyl succinic anhydride and maleic anhydride. TheC₈ ABSA was left as a bottoms product (1000 g, 3.2 mols). The ABSA ischaracterized by carbonyl absorption peaks in the infrared at 1770 cm⁻¹and 1855 cm⁻¹.

EXAMPLE 2 Thermal Preparation of Spirodilactone from C₈ ABSA

The C₈ ABSA (100 g) was charged to a vacuum distillation apparatusequipped with a 2-tray Oldershaw column and reflux condenser. Heatingwas by means of an oil bath. The reaction flask was immersed in the hotoil at a temperature of 250°-270° C for a period of about 2.5 hours,during which gas evolved and the following fractions of liquid overheadwere collected:

    ______________________________________                                               Flask     Overhead,  Vacuum, Weight,                                   Fraction                                                                             ° C                                                                              ° C mm Hg   g                                         ______________________________________                                        1      256-245   150-227    6-2.5   10.6                                      2      245-250   214-222     2.2    21.6                                      3      250-260   217-211     2.1     9.1                                      ______________________________________                                    

The overhead product from the above reaction and one other run from thesame feed were combined (48.6 g total) and distilled through ashort-path microstill. The following fractions were collected:

    ______________________________________                                                Bath,     Overhead,  Vacuum, Weight,                                  Fraction                                                                              ° C                                                                              ° C mm Hg   g                                        ______________________________________                                        1       205-210   118-198    0.4-0.8 8.7                                      2       214       203-206    0.8     19.3                                     3       215-233   223-228    2.1-2.2 11.8                                     4       239-255   230        2.1-2.2 6.1                                      Bottoms --        --         --      1.9                                      ______________________________________                                    

The molecular weight of the overhead product was measured byhigh-resolution mass spectrometry as 264.1365. The theoretical molecularweight for the spirodilactone from C₈ ABSA is 264.1362, corresponding tothe formula C₁₅ H₂₀ O₄. The spirodilactone has a carbonyl absorption inthe infrared spectrum of 1790 cm⁻¹. The presence of a trans-double bondwas shown by a 1666 cm⁻¹ absorption in the Raman spectrum of fractionnumber 2.

EXAMPLE 3 Spirodilactone from C₃ ABSA

Propenyl bis(succinic anhydride) (100 g) contained in a 100-mlround-bottom flask equipped with a microstill head was heated in a oilbath, and the following fractions were collected:

    ______________________________________                                                   Flask      Vacuum,    Weight,                                      Fraction   ° C mm Hg      g                                            ______________________________________                                        1          225-232    5.5        3.5                                          2          225-232    5.5-2      4.0                                          3          227-235    2-1        4.4                                          4          235-250    1.5-2      4.8                                          ______________________________________                                    

Infrared spectra indicated that Fractions 2-4 were essentially identicaland were a mixture of spirodilactone, anhydride and a product containingfree carboxylic acid groups.

In accordance with the present invention, it has also been found thatthe formation of the spirodilactones is substantially accelerated byhaving a base present. In general, organic bases, e.g., heterocyclic ortrialkyl tertiary amines, or quaternary ammonium hydroxides arepreferred, but other bases such as potassium cyanide and sodiumhydroxide may be used. Typical experiments showing the catalytic effectof bases are given in the following examples.

EXAMPLE 4 Catalytic Formation of the Spirodilactone from C₈ ABSA

The effect of additives on the formation of spirodilactone was evaluatedby placing 1 g of C₈ ABSA in a Fischer-Porter pressure tube of volume 94ml and equipped with a pressure gauge, inlet valve and outlet valve. Thetube was heated by immersion in an oil bath. After the ABSA and catalystwere placed in the tube, it was flushed with nitrogen several times,degassed under vacuum, and placed under nitrogen at atmosphericpressure. It was then placed in an oil bath at the desired temperatureand the reaction time, bath temperature, and pressure in the tuberecorded. Usually 3 tubes were run at one time.

The control tube containing only C₈ ABSA was held at 220° C for 6.5hours until the pressure reached 20 psi and stopped increasing.Hydroquinone (0.05 g) plus C₈ ABSA (1 g) in a similar tube reached amaximum pressure of 22 psi in 6.5 hours. The infrared spectra of the twoproducts were almost identical and showed that they were essentiallyspirodilactones and contained a trace of anhydride. A similar runcontaining dimethylaniline (0.03 g) and C₈ ABSA (1 g) reached a pressureof 24 psi in 2 hours. The infrared spectrum was that of thespirodilactone. All runs were carried out in the same oil bathmaintained at 220° C. The presence of CO₂ in the vapor was shown byanalysis with a Fischer gas partitioner.

A series of such tests was carried out with a variety of bases and at avariety of temperatures without catalyst. The results are shown in thefollowing Table I.

                                      TABLE I                                     __________________________________________________________________________                                     Anhydride                                                   Weight,                                                                            Temp.,                                                                            Time,                                                                             Pressure,                                                                          Present in                                   Test                                                                             Additive    %    ° C                                                                        hrs psi  SDL.sup.1 by IR                              __________________________________________________________________________    1  Pyridine    3    220 0.7 24   None                                         2  2,2'-Bipyridyl                                                                            3    220 1   23   None                                         3  Benzyl trimethyl-                                                             ammonium hydroxide                                                                        5    180 2   28   None                                         4  N,N-dimethyldodecyl-                                                          amine       10   200 1   23   None                                         5  Octanoic acid                                                                             5    200 6   21   Trace                                        6  None        --   200 21  23   Moderate                                     7  None        --   220 6   21   Trace                                        8  None        --   240 4   23   None.sup.2                                   9  None        --   255 2   31   None.sup.3                                   __________________________________________________________________________     .sup.1 Spirodilactone                                                         .sup.2 After 5 hours                                                          .sup.3 After 3.5 hours                                                   

The above results show that a variety of tertiary amines and quaternaryammonium salts will catalyze the conversion of the ABSA to thespirodilactones. On the other hand, organic acids and free radicalinhibitors do not affect the reaction -- the product beingspirodilactone as in a control without any additive. Acids such astoluene sulfonic acid caused evolution of CO₂, but the spirodilactoneformation was low. Zinc chloride gave a mixture of spirodilactone anddecomposition products. Bases such as sodium hydroxide and potassiumcyanide also catalyzed the decarboxylation of ABSA, but they caused theformation of some tarry by-products. Sodium hydride gave a productcontaining a spirodilactone and by-products as well.

EXAMPLE 5 Spirodilactone from C₈ Alkyl Bis(succinic Anhydride)

Octyl bis(succinic anhydride) was heated with 10 weight percentN,N-dimethyldodecylamine at 200° C in the Fischer-Porter tube andassociated equipment described above. After about 1 hour the pressureremained constant, and heating was continued for another 2.5 hours. Theinfrared spectrum of the product was characteristic of thespirodilactone.

The following examples show the preparation of keto diesters and ketodiacids and uses thereof.

EXAMPLE 6 Di(n-Octyl) Ester of the Spirodilactone from C₈ ABSA

The spirodilactone from C₈ ABSA (10 g, 0.038 mol) was added to toluene(20 ml) containing n-octanol (12.9 g, 0.099 mol) and p-toluene sulfonicacid (0.15 g). The mixture was contained in a 100-ml round-bottom flaskequipped with a Dean-Stark trap, condenser and a side arm to removesamples. The system was heated under reflux for 3.5 hours, but theinfrared spectra indicated that the reaction was complete after about 5minutes of refluxing. The mixture was cooled and extracted with 10%aqueous caustic. The organic phase was dried over magnesium sulfate,filtered, and distilled to remove toluene and excess octanol. Theresidue weighed 15.7 g for an 82 mol percent yield. The product wasdistilled at a bath temperature of 160° C and a vacuum of 5×10⁻³ mm Hg.The distilled keto diester was a clear, colorless liquid. It wascharacterized by its carbonyl absorption band in the infrared at 1730cm⁻¹.

EXAMPLE 7 Di(n-Butyl) Ester of the Spirodilactone from C₈ ABSA

This diester was made by refluxing a solution containing thespirodilactone from C₈ ABSA (5.0 g, 0.019 mol), n-butanol (7.2 g, 0.097mol), toluene (40 ml) and p-toluene-sulfonic acid (0.5 g). Water stoppedevolving after about 1 hour under reflux. The cooled solution wasextracted with 10% sodium bicarbonate, and the solvent was removed,leaving the di(n-butyl) ester of the keto diacid corresponding to thespirodilactone from C₈ ABSA. The keto diester product was characterizedby mass spectrometry as having a molecular weight of 394 (theoreticalmolecular weight of 394), and infrared carbonyl absorption at 1730 cm⁻¹.

The di(n-octyl) ester prepared above was evaluated as a plasticizer. Theresults from various tests on polyvinyl chloride (PVC) plasticized bythese materials are given below in Table II, along with values from PVCplasticized with 2 commercial plasticizers.

                                      TABLE II                                    __________________________________________________________________________    Tensile Properties                                                                       Flex.                                                                             100% Break                                                                              Break Shore                                                                              Soap                                                 Temp.,                                                                            Modulus                                                                            Strength                                                                           Elongation                                                                          Hardness                                                                           Water                                     Plasticizer                                                                         Color                                                                              ° C                                                                        psi  psi  %     10 sec.                                                                            Extr..sup.1                                                                       Volatility.sup.2                      __________________________________________________________________________    Prod. Ex. 6                                                                         lt. yellow                                                                         -21 2000 2740 340   88   4.5 4.5                                   DOP.sup.3                                                                           lt. yellow                                                                         -23 1700 2730 350   84   6.7 26.                                   ODTM.sup.4                                                                          colorless                                                                          -21 2400 2720 300   91   1.9 3.                                    __________________________________________________________________________     .sup.1 % loss in weight after 48 hours at 70° C                        .sup.2 % loss in weight after 90 hours at 105° C                       .sup.3 Dioctyl phthalate                                                      .sup.4 Tri (octyl/decyl) mellitate, prepared from commercial mixture of       octanol & decanol                                                        

EXAMPLE 8 Keto Diacid from Spirodilactone from C₈ ABSA

The spirodilactone was heated in aqueous potassium hydroxide (pH 14) forabout 1 hour. The cool solution was acidified to pH 1 with concentratedhydrochloric acid. The keto diacid formed as an oil. Its infraredspectrum had carbonyl absorption peaks at 1710 cm⁻¹ and 1740 cm⁻¹,corresponding to the keto diacid.

While the character of this invention has been described in detail withillustrative examples, this has been done by way of illustration onlyand without limitation of the invention. It will be apparent to thoseskilled in the art that modifications and variations of the illustrativeexamples may be made in the practice of the invention within the scopeof the following claims.

I claim:
 1. Polyvinyl chloride plastic compositions containing amountssufficient to impart plasticizing properties of the cyclic keto estersof spirodilactones from alkenyl or alkyl bis(succinic anhydride) havingthe formula ##STR5## in which R is alkyl or alkenyl of 2 to 28 carbonatoms and R' groups, which may be the same or different, are hydrogen oralkyl groups of 1 to 8 carbon atoms each.